| 摘要 |
<p>A method is provided of cleaving a strip by tensile stress applied by a pulse laser point heat source by shifting a pulse-heating position of the pulse laser point heat source on the basis of both an optimum distance "D" of a center position of a pulse beam spot of the pulse laser point heat source irradiated on the strip from a tip of a crack of the strip and an optimum pulse time "t" of the pulse laser point heat source, wherein the optimum distance "D" and the optimum pulse time "t" are determined by the steps of : pre-determining "t" to find a value of 4 kappa t/W<2> where " kappa " is a thermal diffusivity of the strip, "W" is a width defined as a distance between a cleaving-intended line and a side edge of the strip ; and finding an optimum value of D/W from the value of 4 kappa t/W<2> with reference to a previously obtained relationship between the optimum value of D/W and the value of 4 kappa t/W<2> thereby to find the optimum distance "D". The optimum distance "D" is found so that if the value of 4 kappa t/W<2> is in the range of 0.0001-0.05, then the optimum value of D/W is 0.1, if the value of 4 kappa t/W<2> is in the range of 0.005-1.0, then the optimum value of D/W is 0.2, and if the value of 4 kappa t/W<2> is not less than 1.0, then the optimum value of D/W is 0.4. <IMAGE></p> |
